Detergent lubricant compositions for closed emission internal combustion engines



United States Patent Office 3,405,065 Patented Oct. 8, 1968 4 Claims.(Cl. 252-515) ABSTRACT OF THE DISCLOSURE Mineral lubricating oilcomposition contains the combination of nitrogenous ashless detergentand ethylene glycol monoalkyl ether.

This application is a continuation of Ser. No. 580,892, filed Sept. 21,1966, and now abandoned, and a continuation-in-part of Ser. No. 468,517,filed June 30, 1965, and now abandoned.

This invention relates to novel lubricating oil compositions. Moreparticularly, the invention is concerned with superior new ashlessdetergent lubricating oil compositions for use in spark ignition,internal combustion engines equipped with valve-controlled positivecrankcase ventilation systems.

In recent years spark ignition, internal combusion engines have beenequipped with a positive crankcase ventilation (PCV) system to reducethe fumes normally produced by the operation of such engines. Thissystem commonly comprises a tube or other conduit connecting thecrankcase to the air-fuel intake system such as the carburetor or intakemanifold of the engine. Since the pressure conditions in both thecarburetor and the crankcase may vary widely, it is the usual practiceto connect the crankcase and intake system through a control valve,orifice or other pressure control means. This control preventsabnormally high vacuums which occur from time to time during normalengine operation from imposing a vacuum on the crankcase which mightpull oil along with the fumes from the crankcase.

In the normal operation of PCV systems, particularly those includingcontrol valves, the systems become plugged with carbon deposits andsludges due to the condensatiOn of oil vapors and other materials foundin crankcase fumes. This plug results in improper carburetor mixtures,causing poor idling and stalling. Also, crankcase ventilation isreduced, leading to increased engine sludge.

In the past, maintenance of PCV systems has required that the motoristeither replace the valve periodically or remove it and clean it in asuitable solvent. In practice this was not often done due to the expenseand inconvenience usually associated with any sort of engine overhaul,as well as lack of understanding for the need for periodic servicing.

In accordance with the present invention, a superior new ashlessdetergent lubricating oil composition has been discovered whichcomprises a major proportion of mineral lubricating oil, a minorproportion suflicient to improve the detergent characteristics thereofof a nitrogenous ashless detergent obtained by the acylation of alkylenepolyamines having from 2 to 20 carbon atoms and from 2 to 10 nitrogenatoms with alkenylsuccinic acid or alkenylsuccinic anhydride having fromabout 30 to about 400 carbon atoms in the alkenyl group and from about 2to about 10% by weight of ethyleneglycol monoalkyl ether having 1 to 3ethyleneglycol units and from 1 to 8 carbon atoms in the alkyl group.

The ashless detergent lubricating oil compositions of the presentinvention derive greatly improved operation of spark ignition, internalcombustion engines equipped with valve-controlled positive crankcaseventilation sys tems, particularly those wherein fumes are withdrawnfrom the crankcase intake system. Proper fuel-air ratios are maintained,thus resulting in easier starting, better warm-up without stalling andimproved idling. There is also a remarkable improvement in prevention ofcarbonaceous or sludge-type deposits on oil screens, piston rings andother engine parts, as well as decreases in ring and cylinder wear.

The nitrogenous ashless detergents are prepared by heating the alkylenepolyamine and alkenylsuccinic acid or alkenylsuccinic anhydride with theremoval of water. The temperature of the reaction will generally be fromabout 200 to about 500 F., more particularly from about 225 F. to about400 F. The mol ratio of the polyamine to the succinic acid or anhydridewill generally be in the range of from about 0.5 :1 to about 1.5 :1,more particularly from about 0.821 to about 1.2: 1. The time for there-. action will generally be from about 10 minutes to about 12 hours ormore, usually in the range of about 20 minutes to about 6 hours. Ifdesired, the reactants may be employed with an inert reaction medium,such as a hydrocarbon, for example, mineral lubricating oil. In suchcase, the concentration of the reactants may range from about 1 to 90%by weight, but will usually be from about 25 to by weight of the totalreaction mixture. During the reaction, it may be desirable to removewater formed from the reaction, as for example by distillation.Subatmospheric pressures may be used for this purpose with advantage.

The amine with which the alkenylsuccinic acid or alkenylsuccinicanhydride reacted preferably has at least one primary amino group. Thenitrogen atoms are joined by alkylene groups of from 2 to 6 carbonatoms, preferably of from 2 to 3 carbon atoms, except the primary aminogroups will be substituted with hydrogen or lower alkyl groups of from 1to 6 carbon atoms, more usually from 1 to 3 carbon atoms. Nitrogen atomsmay be present as a heterocyclic ring.

The polyalkyl polyamine reactant is illustrated by the following generalformula:

wherein A is an alkylene radical containing from about 2 to 6 carbonatoms, R is a member of the group consisting of hydrogen and alkylradicals containing from about 1 to 6 carbon atoms, x is a number from 0to 10, y is a number from 0 to 2, and z is a number from 0 to 1, thetotal of x+y+z being a number from 1 to 10.

Illustrative alkylene polyamines of the foregoing types areethylenediamine, diethylenetriamine, triethylenetetramine,dipropylenetriamine, dimethylaminopropylamine, tetraethylenepentamine,N-aminoethyl piperazine, pentaethylenehexamine, nonaethylenedecamine,etc.

The alkenylsuccinic acid or alkenylsuccinic anhydride reactant isillustrated by the following structural formula for the anhydride:

0 RCH o CHPfi wherein R is a hydrocarbon radical having from 30 to 400carbon atoms, preferably from about 50 to about 200 carbon atoms.

The R'radical of tli'ej'above formula, that is, the alkenyl radical, isreadily obtained by polymerizing olefins of from 2 to 5 carbonatomsfsuch as propylene, ethylene, isobutylene, pentene, etc., andmixtures thereof. Methods of polymerization are well known in the art,e.g., US. Patents Nos. 3,024,237, 3,024,195 and 3,018,291.

The preferred acylated alkylene polyamines are the monoalkenylsuccinimides of tetraethylenepentamine of the formula:

wherein R is a polyolefin radical of from 30 to 200 carbon atoms and isderived from an olefin of 2 to 5 carbon atoms.

The nitrogenous ashless detergents of the lubricating oil compositionsof the invention are employed in amounts sufficient to improve thedetergent characteristics. Ordinarily, amounts of from about 0.1 toabout by weight are satisfactory for this purpose.

The ethyleneglycol monoalkyl ether is preferably the diethylenemonobutyl ether. However, other glycol ethers or mixtures thereof withinthe aforementioned general class may be employed. Such glycol ethersinclude diethyleneglycol monoethyl ether (Carbitol), diethyleneglycolmonomethyl ether (Methyl Carbitol), diethyleneglycol monobutyl ether(Butyl Carbitol), ethyleneglycol monoethyl ether (Cellosove),ethyleneglycol monomethyl ether (Methyl Cellosolve), and ethyleneglycolmonobutyl ether (Butyl Cellosolve).

The .base oil in the lubricant composition of the invention is any oilof lubricating viscosity. Thus, the base oil can be a refinedparaffin-type base oil, a refined naphthenic-type base oil, or asynthetic hydrocarbon or synthetic nonhydrocarbon oil of lubricatingviscosity. As synthetic oils, suitable examples include oils obtained bypolymerization of lower molecular weight alkylene oxides, such aspropylene oxide and/or ethylene oxide employing alcohol or acidinitiators, such as lauryl alcohol or acetic acid. Still other syntheticoils include esters, e.g., di-(2- ethylhexyD-sebacate,tricresylphosphate and silicate esters, such astetra-(Z-ethylhexyl)-orthosilicate and hexa-(2- ethylbutoxy)-disiloxane. For present purposes the mineral lubricating oils are preferred,since they show the greatest improvement.

' Lubricant compositions within the scope of the present invention mayalso contain still other additives of conventional types, such as pourpoint depressants, oiliness and 4 extreme pressure agents, antioxidants,dyes, blooming agents and the like.

Illustrative lubricant compositions of the aforementioned types mayinclude,, f or example, from about 0.1 to about 10% by weight ofalkalineearth'metal, higher alkylphenatedetergent andwear reducingagents. such as the calcium alkylphenate having mixed alkyl groups of 12to 15 carbon atoms. They may also-include from about 0.1 to 10% byweight of organic thiophosphate corrosion and high temperature oxidationinhibitors, such as'the reaction product of pinene andP s the reactionproduct of polybutene and P 55, andfthe bivalentmetal dihydrocarbondithiophosphates, zinc butyl hexyl dithiophosphate and zincdi-(tetradecylphenyl) dithiophosphate. Metal salt detergents in amountsfrom about 0.1 to 10% which may also be used are the calcium petroleumsulfonates of the oil-soluble mahogany type and the calciumnaphthenates.

The operation of. a spark ignition, internal combustion engine withpositive crankcase ventilation (PCV) employing a crankcase lubricatingoil containing glycol ether is illustrated in a series of tests. In thetests,"a 1964 Ford car with a 6-cylinder engine was employed. A varietyof lubricating oil compositions were evaluated, including two used oils.The fuel was a conventionalpremium-grade leaded gasoline.

In the tests the crankcase ventilation system included a typicalspring-loaded ball control valve known as the General Motors AC system.Oil A was a multigrade SAE 10W-30 lubricating oil consisting of asolvent-refined 130 neutral mineral lubricating oil base .along withabout 8% by weight of dodecylmethacrylate vinyl pyrrolidone copolymerashless detergent, 1% zinc butyl hexyldithiophosphate, and about 0.5%tetrapropenylsuccinic acid rust inhibitor. Oil B was a solvent-refinedSAE 30 mineral lubricating oil containing copolymer ofdodecylmethacrylate, polyethyleneglycol (1800 molecular weight)methacrylate and N-aminoethyl piperazine-glycidylmethacrylate copolymeras ashless detergent in combination with zinc butyl hexyldithiophosphate oxidation-corrosion inhibitor. Oil C was a typicalMIL-L-2104B SAE 30 lubricating oil containing polyisobutenyl succinimideof tetraethylenepentamine ashless detergent, calcium petroleumsulfonate, calcium tetradecylphenate, zinc di-(tetradecylphenyl)dithiophosphate and zinc butyl hexyl dithiophosphate. Oil D was similarto Oil A except that it contained in addition about 3% of thepolyisobutenyl succinimide of tetraethylenepentamine, having about 65carbon atoms inthe polyisobutenyl group. Oil E was a solvent-refinedmineral lubricating oil base containing calcium petroleumsulfonate,calcium tetradecylphenate and zinc butyl hexyl dithiophosphate asdetergent and oxidation-corrosion inhibitor. Oils F and G were used,conventional spark ignition, internal combustion engine lubricating oilsof undetermined constitution.

TABLE I Flow rate at 14 in. Hg 011 Net Type service Ap, c.t.m. 1

miles Initial Final AMultigrade SAE 10W-30 10 1. 80 2. 63 10 1. 2. 60B-Single Grade SAE 30 10 1.60 2. 60 10 0. 2. C-MIL-L-2104B SAE 30 101.70 2. 10 1.00 2. 60 DMS Quality SAE 10W-30 10 1. 2. 60 10 1. 20 2. 65E-ML Single Grade SAE 30 10 1. 82 2. 65 l0 1. 55 2. 62

E-MS Single Grade SAE 30 10. 0.30 2. 50 D-MS Multlgrade SAE 10W-30 100.30 2. 60 F-Used Test Oil N0. 1 from Lab En 10 1. 72 e 2. 60 G-UscdTest Oil No. 2 from Lab Eng 10 '.do... 1. 40 2. 60 A-Multigrade SAE10W-30 7 Aunt Minnie (short ps 0t 1. 55 2. 60

0.5 to 2.0 mi. in-length). A-Hultlgradt) SAE 10W-30 7. 6 Chassis Dyna.at; 40 F. 1.80 60 after 12-hr. soak at 40 F. 0 1 hr. of idling"; 25 2.30

Clean Flow Rate at 14 In. Hg Ap=2.60 c.f.n1.

The tests were carried out in general on the basis of miles city-typeservice. In addition, a test was made with the car operating onso-called Aunt Minnie service with short trips of /2 to 2 miles withintermittent cold soaking, during which the engine was allowed to coolto ambient temperatures. In still another test the performance wasevaluated on a chassis dynamometer where the car had been cold soaked at40 F. for 12 hours prior to adding the glycol ether. Also, the clean-upeffect of one hour of idling of the engine was determined. In each casethe glycol ether was diethyleneglycol monobutyl ether, and was employedin an amount of about 3% by weight based on the total crankcaselubricating oil composition.

Briefly summarized, the essential procedure of the tests involvedmeasuring the initial flow rate of the PCV control valve and the finalflow rate, each in cubic feet per minute at 14 inches of mercurydifferential pressure, the latter being approximately the pressuredifferential (vacuum) obtained in normal engine operation with the valveclosed. The test results are shown in the preceding Table I.

The above test results show that the PCV systems of spark ignition,internal combustion engines are markedly improved 'by the operation ofthe engine with crankcase lubricating oil compositions containingdiethyleneglycol monobutyl ether. A satisfactory clean-up which returnsthe PCV system to practically new performance is obtained within 10miles of operation under normal types of service. Thus, it was notnecessary for the system to be removed for cleaning or replacement.

In addition to the foregoing tests, the effect of ethyleneglycolmonoalkyl ether in combination with nitrogenous ashless detergent as thesole detergent in lubricating oil compositions was determined. Thelubricating oil composition is mixed with pyruvic acid at aconcentration of 100 grams of acid per kilogram of oil. The mixture isheated at 284 F. for /2 hour. After standing about hours, the weight ofsedimented insoluble resin formed is measured. Low values indicate gooddetergency, and the procedure is found to correlate with actual sparkignition internal combustion engine operation.

Using the aforementioned procedure, the addition of a typicalnitrogenous ashless detergent additive package to a solvent-refined SAE30 mineral base oil was found to give 13.4 grams per kilogram ofinsoluble resin, whereas the addition of nitrogenous ashless detergentin combination with ethyleneglycol monoalkyl ether actually lowered theinsoluble resin formation to 8.8 grams per kilogram. This is surprising,since the presence of polyglycol ethers usually detracts from theeffectiveness of detergents in lubricating oil compositions. Thepolyglycol ether in similarly compounded mineral oil omitting thedetergent gave 67.7 grams per kilogram resin.

The nitrogenous ashless detergent additive mentioned above waspolyisobutenyl succinimide of tetraethylenepentamine having about 65carbon atoms in the polyisobutenyl group. The compound lubricating oilcomposition contained 1.2% by weight alkenyl succinimide, 6 mm./ kg.zinc butyl hexyl dithiophosphate oxidation-corrosion inhibitor and 1mm./kg. zinc di-(tetradecylphenyl) dithiophosphate oxidation-corrosioninhibitor. The similarly compounded mineral oil omitting detergent wassolvent refined mineral base oil containing 12 mm./ kg. zinc butyl hexyldithiophosphate. The ethyleneglycol monoalkyl ether was the diethylenemonobutyl ether and was used in an amount to provide a concentration of3.2% by weight in the lubricating oil composition.

As illustrated above, another embodiment of the present invention liesin the combination of nitrogenous ashless detergent and ethyleneglycolmonoalkyl ether as a new additive combination for lubricating oilcompositions for spark ignition, internal combustion engines. In thisnew combination the weight ratio of nitrogenous ashless detergent toethyleneglycolmonoalkyl ether is generally from about 0.01:1 up to about15:1 and preferably from about 0.3:1 up to about 5:1 for most effectiveengine cleanliness and PCV system operation.

While the character of this invention has been described in detail withnumerous examples, this has been done by way of illustration only andwithout limitation of the invention. It will be apparent to thoseskilled in the art that numerous modifications and variations of theillustrative examples may be made in the practice of the inventionwithin the scope of the following claims.

I claim:

1. Lubricating oil composition which comprises a major proportion ofmineral lubricating oil, a minor proportion sufficient to improve thedetergent characteristics thereof of a nitrogenous ashless detergentobtained by the acylation of alkylene polyamines having from 2 to 20carbon atoms and from 2 to 10 nitrogen atoms with alkenylsuccinic acidor al kenylsuccinic anhydride having from about 30 to about 400 carbonatoms in the alkenyl group and from about 2 to about 10% by weight ofethyleneglycol monoalkyl ether having 1 to 3 ethyleneglycol units andfrom 1 to 8 carbon atoms in the alkyl group.

2. A lubricating oil composition in accordance with claim 1 in which theethyleneglycol monoalkyl ether is diethyleneglycol monobutyl ether.

3. A- lubricating oil composition in accordance with claim 1 wherein thenitrogenous ashless detergent is the monoalkenyl succinimide oftetraethylenepentamine of the formula:

wherein R is a polyolefin radical of from 30 to 200 carbon atoms and isderived from an olefin of 2 to 5 carbon atoms.

4. A lubricating oil composition in accordance with claim 3 wherein theethyleneglycol monoalkyl ether is diethyleneglycol monobutyl ether.

No references cited.

PATRICK P. GARVIN, Primary Examiner.

